The present disclosure relates to prosthetic heart valve implantation and, more particularly, to assemblies and methods for loading a self-expanding collapsible heart valve into a delivery device.
Prosthetic heart valves may be formed from biological materials such as harvested bovine valves or pericardial tissue. Such prosthetic valves are typically fitted within a stent, which may be inserted into the heart at the annulus of the compromised native valve to replace the functioning of the native valve. To perform such insertion procedure using a minimally invasive technique, it is typically necessary to compress the stent to a reduced diameter for loading into the delivery device.
In the case of prosthetic valves formed from biological materials, the stented valve is preferably preserved in the open condition for storage as compression of the valve material for extended periods may compromise the integrity of the biological valve. It may therefore be necessary to crimp the valve, or reduce its diameter for loading into the delivery device, in the operating arena.
Present crimping devices and methods for collapsing a stented valve, including direct radial assemblies, have proven to be unsatisfactory as they include bulky assemblies, are difficult to master, are time consuming to use, impart undue stress on the stented valve, and/or exhibit other undesirable qualities. Moreover, it is sometimes difficult to securely engage the stent with a retaining element of the delivery device. Further, prosthetic heart valves that incorporate two separate cuff layers may present particular difficulties in loading the valve into the delivery device, which are not encountered with prosthetic heart valves that incorporate a single cuff layer. It would therefore be beneficial to be able to collapse a stented bioprosthetic heart valve using apparatus and techniques that overcome the deficiencies of conventional devices. In addition, such devices and methods could be useful in loading the collapsed stented valve into a minimally invasive delivery device.